yet more cleanup between sessions. should help with nurbs/polys stuff

pandatool/src/mayaprogs/mayaToEgg_server.cxx

@@ -316,6 +316,7 @@ run() {
   close_output();
   _verbose = 0;
   _polygon_tolerance = 0.01;
+  _polygon_output = 0;
   _transform_type = MayaToEggConverter::TT_model;
   _subsets.clear();
   _subroots.clear();